1938, coined, according to DuPont, from a random generic syllable nyl- + -on, a common ending in fiber names (compare rayon and later Dacron), said to be ultimately from cotton. "Consumer Reports" in 1939 called it "duPont's much-publicised new miracle yarn, which is scheduled to appear in 5,000,000 stockings next year and which is meantime giving rise to many rumors, hopes and fears." As an adjective from 1939. Nylons for "nylon stockings" is from 1940.
Nylon is the generic name chosen by the Dupont Company for a group of materials classed as synthetic linear superpolymers. It has also been defined as a "Man made protein-like chemical product (polyamide) which may be formed into fibers, bristles, sheets, and other forms, characterized when drawn by extreme toughness, elasticity, and strength." ["The Michigan Technic," August 1945]